Disc drives are used for data storage in modem electronic products ranging from digital cameras to computers and network systems. Ordinarily, a disc drive includes a mechanical portion, or head disc assembly, and electronics in the form of a printed circuit board assembly mounted to an outer surface of the head disc assembly. The printed circuit board assembly controls functions of the head disc assembly and provides a communication interface between the disc drive and a host being serviced by the disc drive.
Typically, the head-disc assembly has a disc with a recording surface rotated at a constant speed by a spindle motor assembly and an actuator assembly positionably controlled by a closed loop servo system. The actuator assembly supports a read/write head that writes data to and reads data from the recording surface.
The disc drive market continues to place pressure on the industry for disc drives with increased capacity at a lower cost per megabyte, higher rates of data throughput between the disc drive and the host and improved reliability.
Crash stops have an important role to play in modem reliable disc chive assemblies. They not only provide a boundary within which the actuator assembly operates, but also protect the read/write head from damage by inhibiting interaction between the read/write head and components near the inner diameter of the disc, and by preventing the read/writehead from extending beyond the outer diameter of the disc.
Prior art crash stops have typically been made from molded rubber or polymer and have generally been inserted into either the basedeck or a pole piece of the voice coil motor. Difficulties surrounding the use of crash stops include: misalignment of crash stops relative to mounting locations; dislodging of the crash stops during disc drive operations following misalignment during the assembly process; inconsistency in placement of the crash stops leading to reliability issues; costly methods of assembling the crash stops into head disc assemblies, and limitations on the rigidity of materials used.
As such, challenges remain and a need persists for improvements in crash stops for use in disc drive type applications.